/* 全局样式重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px; /* 为粘性导航栏预留空间 */
}

.card-rating {
    display: flex;
    gap: 2px;
    color: #faad14;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Helvetica Neue', Helvetica, Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f5f5;
}

.container {
    width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 顶部导航栏样式 */
.header {
    background-color: #fff;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
    margin: 0;
    padding: 0;
    border-bottom: none;
    overflow: visible;
}

.header-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 15px 0;
}

.logo {
    display: flex;
    align-items: center;
    font-size: 24px;
    font-weight: bold;
    color: #00a854;
}

.logo i {
    margin-right: 10px;
    font-size: 30px;
}

.nav-links {
    display: flex;
    gap: 30px;
}

.nav-link {
    text-decoration: none;
    color: #333;
    font-size: 16px;
    font-weight: 500;
    transition: color 0.3s;
}

.nav-link:hover {
    color: #00a854;
}

.user-actions {
    display: flex;
    align-items: center;
    gap: 20px;
}

.search-box {
    display: flex;
    align-items: center;
    background-color: #f5f5f5;
    border-radius: 4px;
    padding: 8px 12px;
    width: 280px;
}

.search-box input {
    border: none;
    background: transparent;
    outline: none;
    flex: 1;
    font-size: 14px;
}

.search-btn {
    background: none;
    border: none;
    color: #999;
    cursor: pointer;
    font-size: 16px;
}

.user-avatar img {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    cursor: pointer;
}

/* 课程导航样式 */
.course-nav {
    background-color: #fff;
    border-bottom: 1px solid #e8e8e8;
    margin: 0;
    padding: 0;
    border-top: none;
    margin-top: -2px;
    box-shadow: none;
}

.course-nav-links {
    display: flex;
    gap: 40px;
    padding: 15px 0;
}

.course-nav-link {
    text-decoration: none;
    color: #333;
    font-size: 16px;
    font-weight: 500;
    transition: color 0.3s;
    position: relative;
}

.course-nav-link.active {
    color: #00a854;
}

.course-nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -16px;
    left: 0;
    width: 100%;
    height: 3px;
    background-color: #00a854;
}

/* 面包屑导航样式 */
.breadcrumb {
    padding: 15px 0;
    font-size: 14px;
    color: #666;
}

.breadcrumb a {
    color: #666;
    text-decoration: none;
}

.breadcrumb a:hover {
    color: #00a854;
}

.breadcrumb .current {
    color: #333;
    font-weight: 500;
}

/* 主要内容区域样式 */
.main-content {
    padding: 20px 0 40px;
    min-height: 600px;
}

/* 资料详情样式 */
.material-detail {
    background-color: #fff;
    border-radius: 8px;
    padding: 30px;
    margin-bottom: 20px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
}

.material-info {
    margin-bottom: 30px;
}

.info-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    margin-bottom: 20px;
}

.info-title h1 {
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 10px;
    line-height: 1.4;
}

.course-badge {
    display: flex;
    gap: 10px;
}

.badge {
    display: inline-block;
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 12px;
    font-weight: 500;
}

.badge.primary {
    background-color: #e6f7ef;
    color: #00a854;
    border: 1px solid #91d5ff;
}

.badge {
    background-color: #fff2e8;
    color: #fa8c16;
    border: 1px solid #ffd591;
}

.info-actions {
    display: flex;
    gap: 10px;
}

.action-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 8px 16px;
    border: 1px solid #d9d9d9;
    background-color: #fff;
    border-radius: 4px;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.3s;
    gap: 6px;
}

.action-btn:hover {
    border-color: #00a854;
    color: #00a854;
}

.action-btn.primary {
    background-color: #00a854;
    color: #fff;
    border-color: #00a854;
}

.action-btn.primary:hover {
    background-color: #008744;
    border-color: #008744;
    color: #fff;
}

.action-btn.download {
    background-color: #1890ff;
    color: #fff;
    border-color: #1890ff;
}

.action-btn.download:hover {
    background-color: #40a9ff;
    border-color: #40a9ff;
    color: #fff;
}

.info-meta {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
    font-size: 14px;
    color: #666;
}

.meta-item {
    display: flex;
    align-items: center;
    gap: 5px;
}

/* 内容包装器样式 */
.content-wrapper {
    display: grid;
    grid-template-columns: 1fr;
    gap: 30px;
}

/* 评分统计区域样式 */
.rating-stats {
    background-color: #fff;
    border-radius: 8px;
    padding: 20px;
    border: 1px solid #e8e8e8;
    width: 100%;
}

/* 单独的评分系统样式 */
.submit-rating-section {
    background-color: #fff;
    padding: 20px;
    border-radius: 8px;
    margin-bottom: 20px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.submit-rating-section h4 {
    font-size: 16px;
    font-weight: 600;
    color: #333;
    margin-bottom: 15px;
}

.rating-system {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.rating-title {
    font-size: 14px;
    color: #666;
}

.rating-stars-large {
    display: flex;
    gap: 10px;
    margin-bottom: 10px;
}

.rating-stars-large i {
    font-size: 24px;
    color: #faad14;
    cursor: pointer;
    transition: color 0.3s;
}

.rating-stars-large i:hover {
    color: #ff7a45;
}

.submit-rating-btn {
    align-self: flex-start;
    padding: 8px 20px;
    background-color: #00a854;
    color: white;
    border: none;
    border-radius: 4px;
    font-size: 14px;
    cursor: pointer;
    transition: background-color 0.3s;
}

.submit-rating-btn:hover {
    background-color: #008c45;
}

.submit-rating-btn:disabled {
    background-color: #d9d9d9;
    cursor: not-allowed;
}

.rating-stats h3 {
    font-size: 18px;
    font-weight: 600;
    color: #333;
    margin-bottom: 20px;
}

/* 平均评分样式 */
.rating-overview {
    margin-bottom: 20px;
}

.rating-average {
    display: flex;
    align-items: flex-end;
    gap: 15px;
}

.average-score {
    font-size: 48px;
    font-weight: 600;
    color: #faad14;
    line-height: 1;
}

.average-stars {
    display: flex;
    gap: 2px;
    color: #faad14;
    font-size: 20px;
    margin-bottom: 4px;
}

/* 评分分布样式 */
.rating-distribution {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.rating-bar {
    display: flex;
    align-items: center;
    gap: 10px;
}

.rating-label {
    width: 40px;
    font-size: 14px;
    color: #666;
}

.rating-progress {
    flex: 1;
    height: 8px;
    background-color: #f0f0f0;
    border-radius: 4px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background-color: #faad14;
    transition: width 0.3s ease;
}

.rating-percentage {
    width: 40px;
    text-align: right;
    font-size: 14px;
    color: #666;
}

/* 预览区域样式 */
.preview-section {
    background-color: #fafafa;
    border-radius: 8px;
    padding: 20px;
    border: 1px solid #e8e8e8;
    width: 100%;
}

/* 评论区域样式 */
.comments-section {
    width: 100%;
}

.section-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 20px;
}

.section-header h2 {
    font-size: 20px;
    font-weight: 600;
    color: #333;
}

.preview-controls {
    display: flex;
    align-items: center;
    gap: 15px;
}

.control-btn {
    display: flex;
    align-items: center;
    gap: 5px;
    padding: 6px 12px;
    border: 1px solid #d9d9d9;
    background-color: #fff;
    border-radius: 4px;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.3s;
}

.control-btn:hover {
    border-color: #00a854;
    color: #00a854;
}

.zoom-controls {
    display: flex;
    align-items: center;
    gap: 5px;
    border: 1px solid #d9d9d9;
    border-radius: 4px;
    padding: 2px;
}

.zoom-controls button {
    border: none;
    background: none;
    padding: 4px 8px;
    cursor: pointer;
    color: #666;
}

.zoom-controls button:hover {
    color: #00a854;
}

#zoomLevel {
    min-width: 50px;
    text-align: center;
    font-size: 14px;
}

/* 演示文稿包装器 */
.presentation-wrapper {
    display: flex;
    gap: 20px;
    align-items: flex-start;
    margin-bottom: 20px;
}

/* 主幻灯片区域 */
.main-slide-area {
    flex: 1;
    min-width: 0;
}

/* PPT预览容器样式 */
.presentation-container {
    position: relative;
    width: 100%;
    height: 450px;
    background-color: #fff;
    border: 1px solid #e8e8e8;
    border-radius: 4px;
    overflow: hidden;
}
/* 全屏时填满视口 */
.presentation-container:fullscreen {
    width: 100vw;
    height: 100vh;
}
.presentation-container:-webkit-full-screen {
    width: 100vw;
    height: 100vh;
}

/* 右侧预览区域 */
.preview-sidebar {
    width: 200px;
    background-color: #fff;
    border: 1px solid #e8e8e8;
    border-radius: 4px;
    padding: 15px;
    height: 450px;
    display: flex;
    flex-direction: column;
}

.preview-sidebar h4 {
    font-size: 16px;
    font-weight: 600;
    color: #333;
    margin-bottom: 15px;
    border-bottom: 1px solid #e8e8e8;
    padding-bottom: 10px;
}

/* 垂直缩略图容器 */
.vertical-thumbnails {
    flex: 1;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

/* 预览缩略图样式 */
.preview-thumbnail {
    border: 2px solid transparent;
    border-radius: 4px;
    padding: 10px;
    cursor: pointer;
    transition: all 0.3s;
    background-color: #f5f5f5;
}

.preview-thumbnail:hover {
    border-color: #00a854;
    background-color: #f0f9f5;
}

.preview-thumbnail.active {
    border-color: #00a854;
    background-color: #e6f7ef;
}

.preview-thumbnail-content {
    text-align: center;
}

.preview-thumbnail-text {
    font-size: 12px;
    color: #666;
    margin-bottom: 5px;
}

.preview-thumbnail-title {
    font-size: 14px;
    font-weight: 500;
    color: #333;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.slides-container {
    position: relative;
    width: 100%;
    height: 100%;
}

.slide {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: none;
    transition: transform 0.3s ease;
}

.slide.active {
    display: block;
}

.slide-content {
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    background-color: #fff;
    border-radius: 4px;
    overflow: hidden;
}

.slide-header {
    background-color: #f0f0f0;
    padding: 10px 20px;
    font-size: 14px;
    color: #666;
    border-bottom: 1px solid #e0e0e0;
}

.slide-body {
    flex: 1;
    padding: 30px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
}

.slide-title {
    font-size: 28px;
    font-weight: 600;
    color: #333;
    margin-bottom: 15px;
}

.slide-subtitle {
    font-size: 20px;
    color: #666;
    margin-bottom: 30px;
}

.slide-text {
    font-size: 18px;
    line-height: 1.8;
}

.slide-text p {
    margin-bottom: 10px;
}

.math-formula {
    font-style: italic;
    font-size: 20px;
    margin: 15px 0;
}

/* 翻页控制按钮 */
.nav-btn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: none;
    background-color: rgba(0, 0, 0, 0.3);
    color: #fff;
    font-size: 18px;
    cursor: pointer;
    transition: background-color 0.3s;
    z-index: 10;
}

.nav-btn:hover {
    background-color: rgba(0, 0, 0, 0.5);
}

.prev-btn {
    left: 10px;
}

.next-btn {
    right: 10px;
}

/* 页码指示器 */
.pagination {
    position: absolute;
    bottom: 10px;
    left: 50%;
    transform: translateX(-50%);
    background-color: rgba(0, 0, 0, 0.3);
    color: #fff;
    padding: 4px 12px;
    border-radius: 15px;
    font-size: 14px;
}

/* 缩略图导航样式 */
.thumbnails-container {
    display: flex;
    gap: 10px;
    padding: 10px;
    background-color: #fff;
    border: 1px solid #e8e8e8;
    border-radius: 4px;
    overflow-x: auto;
    display: none;
}

.thumbnail-item {
    min-width: 120px;
    height: 80px;
    border: 2px solid transparent;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.3s;
}

.thumbnail-item:hover {
    border-color: #00a854;
    box-shadow: 0 2px 8px rgba(0,168,84,0.2);
}

.thumbnail-item.active {
    border-color: #00a854;
    box-shadow: 0 2px 8px rgba(0,168,84,0.2);
}

.thumbnail-content {
    width: 100%;
    height: 100%;
    background-color: #f5f5f5;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    color: #666;
}

/* 评论区域样式 */
.comments-section {
    background-color: #fff;
    border-radius: 8px;
    padding: 20px;
    border: 1px solid #e8e8e8;
}



/* 评论过滤样式 */
.comment-filters {
    display: flex;
    gap: 10px;
}

.filter-btn {
    padding: 6px 12px;
    border: 1px solid #d9d9d9;
    background-color: #fff;
    border-radius: 4px;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.3s;
}

.filter-btn:hover {
    border-color: #00a854;
    color: #00a854;
}

.filter-btn.active {
    background-color: #e6f7ef;
    border-color: #00a854;
    color: #00a854;
}

/* 评论搜索样式 */
.comment-search {
    margin-bottom: 20px;
}

.search-input {
    width: 100%;
    padding: 10px 15px;
    border: 1px solid #d9d9d9;
    border-radius: 4px;
    font-size: 14px;
    outline: none;
    transition: border-color 0.3s;
}

.search-input:focus {
    border-color: #00a854;
}

/* 评论输入框样式 */
.comment-input-area {
    display: flex;
    gap: 15px;
    margin-bottom: 20px;
}

.user-avatar-small img {
    width: 40px;
    height: 40px;
    border-radius: 50%;
}

.comment-input-wrapper {
    flex: 1;
}

.comment-textarea {
    width: 100%;
    min-height: 80px;
    padding: 10px 15px;
    border: 1px solid #d9d9d9;
    border-radius: 4px;
    font-size: 14px;
    resize: vertical;
    outline: none;
    transition: border-color 0.3s;
    font-family: inherit;
}

.comment-textarea:focus {
    border-color: #00a854;
}

.comment-input-actions {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-top: 10px;
}

.rating-stars {
    display: flex;
    align-items: center;
    gap: 5px;
    color: #faad14;
}

.rating-stars span {
    color: #666;
    font-size: 14px;
}

.rating-stars i {
    cursor: pointer;
    font-size: 18px;
    transition: color 0.2s;
}

.rating-stars i:hover,
.rating-stars i.active {
    color: #ff7a45;
}

.submit-comment-btn {
    padding: 8px 24px;
    background-color: #00a854;
    color: #fff;
    border: none;
    border-radius: 4px;
    font-size: 14px;
    cursor: pointer;
    transition: background-color 0.3s;
}

.submit-comment-btn:hover {
    background-color: #008744;
}

/* 评论列表样式 */
.comments-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.comment-item {
    display: flex;
    gap: 15px;
    padding-bottom: 20px;
    border-bottom: 1px solid #f0f0f0;
}

.comment-avatar img {
    width: 40px;
    height: 40px;
    border-radius: 50%;
}

.comment-content {
    flex: 1;
}

.comment-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 5px;
}

.comment-author {
    font-weight: 500;
    color: #333;
    font-size: 15px;
}

.comment-rating {
    display: flex;
    gap: 2px;
    color: #faad14;
    font-size: 14px;
}

.comment-time {
    font-size: 12px;
    color: #999;
    margin-bottom: 10px;
}

.comment-body {
    font-size: 14px;
    line-height: 1.8;
    color: #333;
    margin-bottom: 10px;
}

.comment-actions {
    display: flex;
    gap: 20px;
}

.action-btn-small {
    display: flex;
    align-items: center;
    gap: 5px;
    border: none;
    background: none;
    color: #999;
    font-size: 14px;
    cursor: pointer;
    transition: color 0.3s;
}

.action-btn-small:hover {
    color: #00a854;
}

/* 回复样式 */
.reply-item {
    margin-top: 15px;
    padding-left: 30px;
    position: relative;
}

.reply-item::before {
    content: '';
    position: absolute;
    left: 10px;
    top: 20px;
    bottom: 0;
    width: 2px;
    background-color: #f0f0f0;
}

.reply-avatar {
    width: 30px;
    height: 30px;
}

.reply-avatar img {
    width: 100%;
    height: 100%;
    border-radius: 50%;
}

.reply-content {
    margin-left: 10px;
}

.reply-header {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 5px;
}

.reply-author {
    font-weight: 500;
    color: #333;
    font-size: 14px;
}

.reply-badge {
    background-color: #1890ff;
    color: #fff;
    padding: 2px 6px;
    border-radius: 2px;
    font-size: 12px;
}

.reply-time {
    font-size: 12px;
    color: #999;
    margin-bottom: 8px;
}

.reply-body {
    font-size: 14px;
    line-height: 1.8;
    color: #333;
    margin-bottom: 8px;
}

.reply-actions {
    display: flex;
    gap: 15px;
}

/* 加载更多按钮容器 - 外层居中 */
.load-more-container {
    width: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    margin-top: 30px;
    margin-bottom: 20px;
    text-align: center;
    box-sizing: border-box;
}

.load-more-btn {
    padding: 10px 24px;
    border: 1px solid #d9d9d9;
    background-color: #fff;
    border-radius: 4px;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.3s;
    color: #666;
    display: block;
    margin: 0 auto;
}

.load-more-btn:hover {
    border-color: #00a854;
    color: #00a854;
}

/* 相关推荐资料样式 */
.related-materials {
    background-color: #fff;
    border-radius: 8px;
    padding: 30px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
}

.related-materials h2 {
    font-size: 20px;
    font-weight: 600;
    color: #333;
    margin-bottom: 20px;
}

.materials-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(280px, 1fr));
    gap: 20px;
    max-width: 900px;
    margin-left: auto;
    margin-right: auto;
    justify-items: center;
}

.material-card {
    width: 100%;
    border: 1px solid #e8e8e8;
    border-radius: 8px;
    overflow: hidden;
    transition: all 0.3s;
    cursor: pointer;
    background-color: #fff;
}

.material-card:hover {
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    transform: translateY(-2px);
}

.card-cover {
    height: 140px;
    background-color: #f5f5f5;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 48px;
    color: #00a854;
    border-bottom: 1px solid #e8e8e8;
}

.card-content {
    padding: 15px;
}

.card-content h3 {
    font-size: 16px;
    font-weight: 600;
    color: #333;
    margin-bottom: 10px;
    line-height: 1.4;
    height: 40px;
    overflow: hidden;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
}

.card-meta {
    display: flex;
    gap: 10px;
    font-size: 12px;
    color: #666;
    margin-bottom: 10px;
    flex-wrap: wrap;
}

.card-stats {
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 12px;
    color: #999;
}



/* 页脚样式 */
.footer {
    background-color: #fff;
    border-top: 1px solid #e8e8e8;
    padding: 40px 0 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-info .footer-logo {
    display: flex;
    align-items: center;
    font-size: 24px;
    font-weight: bold;
    color: #00a854;
    margin-bottom: 15px;
}

.footer-info .footer-logo i {
    margin-right: 10px;
    font-size: 30px;
}

.footer-info p {
    font-size: 14px;
    color: #666;
    line-height: 1.8;
}

.footer-links h3 {
    font-size: 16px;
    font-weight: 600;
    color: #333;
    margin-bottom: 15px;
}

.footer-links ul {
    list-style: none;
}

.footer-links li {
    margin-bottom: 10px;
}

.footer-links a {
    color: #666;
    text-decoration: none;
    font-size: 14px;
    transition: color 0.3s;
}

.footer-links a:hover {
    color: #00a854;
}

.footer-contact h3 {
    font-size: 16px;
    font-weight: 600;
    color: #333;
    margin-bottom: 15px;
}

.social-links {
    display: flex;
    gap: 15px;
    margin-bottom: 15px;
}

.social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background-color: #f5f5f5;
    color: #666;
    text-decoration: none;
    font-size: 18px;
    transition: all 0.3s;
}

.social-link:hover {
    background-color: #00a854;
    color: #fff;
}

.contact-phone, .contact-email {
    font-size: 14px;
    color: #666;
    margin-bottom: 10px;
}

.footer-bottom {
    text-align: center;
    font-size: 14px;
    color: #999;
    padding-top: 20px;
    border-top: 1px solid #e8e8e8;
}

/* 返回顶部按钮样式 */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background-color: #00a854;
    color: white;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 999;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background-color: #008d45;
    transform: translateY(-3px);
}

.back-to-top:active {
    transform: translateY(-1px);
    box-shadow: 0 1px 5px rgba(0, 0, 0, 0.2);
}

/* 响应式调整 */
@media (max-width: 768px) {
    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 45px;
        height: 45px;
        font-size: 18px;
    }
}

/* 响应式设计 */
@media (max-width: 1200px) {
    .container {
        width: 100%;
    }

    .materials-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 992px) {
    .content-wrapper {
        grid-template-columns: 1fr;
    }

    .nav-links {
        gap: 20px;
    }

    .footer-content {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 768px) {
    .header-top {
        flex-wrap: wrap;
    }

    .nav-links {
        width: 100%;
        justify-content: center;
        margin-top: 15px;
    }

    .course-nav-links {
        overflow-x: auto;
        padding-bottom: 10px;
        white-space: nowrap;
    }

    .materials-grid {
        grid-template-columns: 1fr;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: 30px;
    }

    .presentation-container {
        height: 400px;
    }
}